OVERVIEW

The teaching of Human Physiology I provides the elements to understand the functioning of the apparatuses that oversee vegetative life and their dynamic integration in the maintenance of homeostasis of the organism in healthy humans and to know the principles of application of biophysics and biomedical technologies to medicine.

AIMS AND CONTENT

LEARNING OUTCOMES

The students will reach a full knowledge of the general physiology and functioning of the cardiovascular, respiratory, renal, and digestive systems and the basics of nutritional science and sports physiology and their dynamic integration in maintaining the body's homeostasis

AIMS AND LEARNING OUTCOMES

The purpose of this course is to provide students  with the knowledge of the apparatuses cardiovascular, respiratory, renal, digestive and the basics of nutritional science and sports physiology that oversee vegetative life and their dynamic integration in maintaining the body's homeostasis.

PREREQUISITES

Physiology is the scientific study of the functioning of the living organism, in terms of physical and chemical processes. Students will achieve better results in the understanding physiology if they can rely on solid foundations in mathematics, physics, chemistry, biochemistry and biology. 

TEACHING METHODS

Frontal Lessons

Laboratories of cardicirculatory and respiratory physiology

Any Student with documented Specific Learning Disorders (SLD), or with any special needs, shall reach out to the Lecturer(s) and to the dedicated SLD Representative in the Department before class begins, in order to liase and arrange the specific teaching methods and ensure proper achievement of the learning aims and outcomes.

SYLLABUS/CONTENT

CELLULAR PHYSIOLOGY

Membrane Potential Composition of the intracellular and extracellular fluid compartments. Structure and functional properties of the plasma membrane. Ion movement across the membrane: ion channels and membrane transporters. Principle of electroneutrality. Measurement of membrane potential. Origin of the resting membrane potential. Chemical and electrical gradients. Nernst equation and equilibrium potentials for the major ionic species. Goldman-Hodgkin-Katz equation. Membrane depolarization and hyperpolarization. Na⁺/K⁺-ATPase. Passive membrane properties. Membrane responses to current injection. Equivalent electrical circuit of the cell membrane: membrane conductance and capacitance. Membrane time constant and length constant.

Active Membrane Properties: The Action Potential Non-excitable and excitable cells. Voltage-gated ion channels: structural and functional properties. Phases of the action potential and associated ionic currents. Concepts of threshold, all-or-none response and refractoriness. Principles and applications of voltage-clamp and patch-clamp techniques.

Propagation of the Action Potential Non-decremental propagation of the action potential. Continuous and saltatory conduction. Directionality of action potential propagation.

Role of passive membrane properties and of the myelin sheath in action potential conduction.

Skeletal Muscle Basic anatomical, histological, cellular and molecular organization of skeletal muscle. Actin and myosin. Sarcomere organization. Sliding filament theory and cross-bridge cycle. Neural control of skeletal muscle: motor neurons and motor units, neuromuscular junction and excitation-contraction coupling. Skeletal muscle fibre types. Regulation of muscle force: motor unit recruitment, single twitch, summation, incomplete tetanus and complete tetanus. Isometric and isotonic contractions. Length-tension and force-velocity relationships.

Smooth Muscle Ultrastructure of smooth muscle. Mechanisms of contraction and excitation-contraction coupling. Intercellular junctions in smooth muscle. Mechanical properties and patterns of smooth muscle contraction. Autonomic innervation of smooth muscle and pacemaker potentials. Fast and slow cross-bridge cycling. Latch state.

CARDIOVASCULAR PHYSIOLOGY

Body Fluid Compartments Major body fluid compartments and their physicochemical characteristics. Processes involved in the transfer of solutes and water between compartments: diffusion, hydrostatic pressure and osmotic pressure. Osmolarity and tonicity. Oncotic pressure. Gibbs-Donnan equilibrium. Determination of body fluid compartment volumes using indicator dilution techniques.

General Organization of the Cardiovascular System, Blood and Hemostasis

General features and components of the cardiovascular system. Functional need for a transport and distribution system. Diffusion of gases and nutrients. Functions and general characteristics of the cardiovascular system. Blood and hemostasis. Blood composition: plasma, serum and formed elements. Hematopoiesis and general characteristics of erythrocytes, leukocytes and platelets. Blood volume and mechanisms involved in its regulation. Rheological properties of blood. Hemostasis and the vasomotor response.

Electrical Activity of the Heart Electrical properties of the myocardium: automaticity, conductivity and excitability. Cardiac action potentials and their electrophysiological basis.

Cardiac automaticity: primary and secondary pacemakers. Electrophysiological basis of pacemaker activity and its autonomic modulation. Cardiac conduction system and propagation of the action potential through the myocardium. Accessory conduction pathways. Relationship between cardiac electrical and mechanical events.

Electrocardiography Basic principles of electrocardiography. Cardiac electrical vector. Bipolar and unipolar leads. The electrocardiographic tracing: nomenclature and electrophysiological origin of ECG waves. Normal electrocardiogram in the different leads and principles of ECG interpretation. Mean electrical axis of the heart. Basic concepts of pathological electrocardiography, including rhythm and conduction disorders and ischemic heart disease.

Principles of Hemodynamics Bernoulli’s principle and conservation of flow. Hagen-Poiseuille law. Resistance to blood flow and vascular determinants of resistance. Vessels arranged in series and in parallel. Effects of blood viscosity on vascular resistance. Laminar and turbulent flow. Axial accumulation of red blood cells. Critical velocity. Effects of gravity on the circulation. Diagnostic significance of turbulent blood flow.

Mechanical Properties of Cardiac Muscle Contractile proteins and molecular mechanisms of myocardial contraction. Excitation-contraction coupling: ryanodine receptors and calcium-induced calcium release. Elastic and contractile components of cardiac muscle. Isometric and isotonic contraction. Force-length and force-velocity relationships. Definition of preload and afterload.

The Heart as a Pump Anatomical and functional organization of the cardiac pump: myocardial fibre arrangement, atrioventricular valves and semilunar valves. Mechanical events of the cardiac cycle: pressure, volume and valvular changes. Origin and characteristics of heart sounds. Cardiac murmurs and valvular heart disease. Relationships among electrical, mechanical and acoustic events of the cardiac cycle.

Myocardial bioenergetics and metabolism. Cardiac work and mechanical efficiency. Application of Laplace’s law to the heart. Intrinsic regulation of cardiac function: homeometric and heterometric regulation of contractility. Frank-Starling mechanism.

Extrinsic regulation of heart rate and myocardial contractility. Ventricular function curves (Sarnoff curves). Heart failure.

General Properties of Blood Vessels Functional organization of the vascular system. Mechanical properties of vascular walls. Elastic and muscular vessels. Transmural pressure. Vascular distensibility and critical closing pressure. Resistance vessels and capacitance vessels. Pressure-volume relationships within the cardiovascular system. Laplace’s law applied to blood vessels.

Arterial Pressure and Pulse Wave Systolic, diastolic and pulse pressure. Elastic properties of large and medium-sized arteries. Arterial pulse wave: generation, components and propagation. Physiological and pathological pulse waveforms.

Measurement of arterial blood pressure.

Microcirculation

Structural organization of the microcirculation. Continuous, fenestrated and discontinuous capillaries. Mechanisms of capillary exchange. Diffusion and filtration. Starling forces and the Starling hypothesis of transcapillary fluid exchange. Lymphatic circulation. Pathophysiology of capillary exchange and edema formation.

Venous Return Hemodynamic determinants of venous return. Venous valves and skeletal muscle pump. Additional mechanisms contributing to venous return. Relationship between venous return and cardiac output.

Control of the Circulation Regional and systemic control of the circulation. Vasomotion. Local autoregulation. Vasodilator metabolites. Regulation of systemic arterial pressure.

Arterial baroreceptor reflex: receptors, afferent pathways, medullary cardiovascular centers and efferent pathways. Hormonal regulation of the circulation. Renal regulation of arterial pressure and pressure diuresis.

Circulation in Specialized Vascular Beds Coronary circulation: hemodynamic characteristics and humoral regulation.

PHYSIOLOGY OF RESPIRATION

Anatomical and Functional Organization and Mechanics of Breathing Respiratory and non-respiratory functions of the lungs. Anatomical, histological and cellular organization of the conducting, transitional and respiratory zones of the airways. Functions of the conducting airways: warming, humidification and filtration of inspired air; mucociliary clearance and cystic fibrosis. Anatomical and physiological dead space. Pulmonary ventilation and alveolar ventilation. Total cross-sectional area, airflow velocity and distribution of airway resistance along the respiratory tract. Changes in airway resistance in relation to lung volume and airflow pattern. Laminar, transitional and turbulent flow; Poiseuille’s law, Reynolds number and Rohrer equation. Modulation of airway resistance by the autonomic nervous system. Respiratory muscles and their mechanical effects. Quiet and forced inspiration and expiration. Pleurae, pleural space and intrapleural pressure; pneumothorax. Definition of lung volumes and capacities. Static spirometry and the Benedict spirometer. Measurement of lung volumes that cannot be determined by conventional spirometry: helium dilution technique and body plethysmography.

Static Mechanics of Breathing Alveolar, intrapleural, transpulmonary and transthoracic pressures, and transmural pressures within the respiratory system.

Pressure-volume relationships of the isolated lung, chest wall and total respiratory system. Relaxation pressure-volume curve of the respiratory system and functional residual capacity. Compliance, specific compliance and elastance, and their physiological and pathological variations. Tissue and alveolar components of pulmonary elastic recoil.

Surface tension, Laplace’s law, pulmonary surfactant, alveolar stability and hysteresis of the pressure-volume curve.

Dynamic Mechanics of Breathing Relationships among pressure, airflow and changes in lung volume during the respiratory cycle. Elastic and resistive components of the work of breathing and their changes during physical exercise and in obstructive and restrictive respiratory disorders. Pulmonary function testing: dynamic spirometry using a flowmeter; volume-time and flow-volume curves; forced vital capacity, forced expiratory volume in one second (FEV₁) and FEV₁/FVC ratio (Tiffeneau index). Dynamic airway compression and equal pressure point. Obstructive and restrictive spirometric patterns.

Respiratory Gases and Alveolar-Capillary Gas Exchange Atmospheric air: composition and changes in gas partial pressures with altitude. Alveolar air: composition and variations in relation to the phase of the respiratory cycle and to different lung regions. Structure of the gas-exchange region and of the alveolar-capillary barrier. Fundamental principles of gas diffusion. Gas equilibration in pulmonary capillaries. Pulmonary diffusing capacity. Diffusion-limited and perfusion-limited gas transfer.

Pulmonary Circulation and Ventilation-Perfusion Relationships Pressure profile within the pulmonary circulation. Pulmonary vascular resistance and its variations in relation to vascular pressures and lung volumes. Hypoxic pulmonary vasoconstriction. Pulmonary blood flow and regional distribution of perfusion. Effects of posture and West’s zones of the lung. Pulmonary capillary transit time at rest and during physical exercise.

Pulmonary ventilation and its regional distribution. Ventilation-perfusion ratio and its regional variations. Ventilation-perfusion mismatch and the major physiological mechanisms underlying hypoxemia.

Transport of Respiratory Gases in Blood Oxygen transport. Oxygen content of arterial and venous blood: physically dissolved oxygen and hemoglobin-bound oxygen.

Major types of hemoglobin and oxygen-hemoglobin dissociation curves. Changes in hemoglobin affinity for oxygen in relation to pCO₂, pH, temperature and 2,3-DPG. Bohr effect and the role of hemoglobin as a buffer. Oxygen exchange in the lungs and peripheral tissues. Carbon dioxide transport. Carbon dioxide content of arterial and venous blood: physically dissolved CO₂, carbamino compounds and the carbonic acid-bicarbonate system. Haldane effect. Carbon dioxide exchange in the lungs and peripheral tissues.

Neural and Chemical Control of Breathing Central neural mechanisms involved in respiratory control: medullary, pontine and forebrain mechanisms. Generation of the respiratory rhythm and the role of the pre-Bötzinger complex. Peripheral neural mechanisms: pulmonary stretch and irritant receptors, vagal afferent endings and pulmonary J receptors. Inflation and deflation reflexes. Proprioceptive, exteroceptive and baroreceptor afferent inputs. Chemical control of breathing. Central mechanisms: physiology of medullary chemosensitive areas. Peripheral mechanisms: physiology of the carotid and aortic bodies. Acute and chronic ventilatory responses to changes in arterial pCO₂, pO₂ and H⁺ concentration. Changes in ventilatory control at high altitude and during sleep.

RENAL PHYSIOLOGY

Functional Anatomy of the Kidney Functional anatomy of the kidney. Basic renal anatomy: renal parenchyma, vascular supply and innervation. The nephron as the functional unit of the kidney: vascular and tubular components. Cortical and juxtamedullary nephrons. Functions of the renal system. Regulation of osmotic balance and body fluid composition. Homeostasis of different chemical species. Acid-base balance. Regulation of nitrogenous waste products. Detoxification. Regulation of arterial blood pressure. Endocrine functions of the kidney: erythropoietin production and vitamin D activation.

Renal Ultrafiltration Filtration and ultrafiltration. Filtrate-to-plasma concentration ratio. Composition of the glomerular ultrafiltrate. Ultrafiltration pressure.

Characteristics of the glomerular filtration barrier: glomerular ultrastructure and selective permeability of the filtration barrier. Effects of molecular size, shape and electrical charge of plasma solutes on their filtration. Glomerular filtration rate and its intrinsic and extrinsic regulation.

Renal Plasma Flow Renal plasma flow. Autoregulation of renal plasma flow and glomerular filtration rate. Myogenic response (Bayliss mechanism), renin-angiotensin system and prostaglandins. Extrinsic neural control.

Tubular Reabsorption and Secretion Processes of tubular reabsorption and secretion. Active and passive mechanisms of tubular transport. Primary and secondary active transport. Tubular reabsorption of glucose: theoretical and empirical renal threshold. Tubular secretion of para-aminohippuric acid (PAH). Renal clearance. Definition and physiological significance of clearance. Determination of glomerular filtration rate by inulin and creatinine clearance. Clearance values of reabsorbed and secreted substances. Determination of renal plasma flow and renal blood flow by PAH clearance. Filtration fraction.

Sodium and Water Reabsorption Central role of sodium transport in renal function. Regulation of urinary sodium excretion. Sodium and water reabsorption along the proximal segments of the nephron. Osmotic diuresis. Generation and maintenance of the corticomedullary osmotic gradient: countercurrent multiplication and the role of the vasa recta. Water reabsorption in the distal segments of the nephron. Mechanism of action of antidiuretic hormone (ADH). Regulation of the balance of other solutes. Tubular handling of urea and urea clearance.

Regulation of Body Fluid Osmolarity and Volume Regulation of body fluid osmolarity and extracellular fluid volume. Osmotic and volume regulation during diuresis and antidiuresis. Osmolar clearance and free water clearance. Osmoreceptors, volume receptors and regulation of ADH secretion. Renal compensatory mechanisms.

Regulation of Acid-Base Balance pH regulation of body fluids. Major physiological buffer systems. Henderson-Hasselbalch equation. Carbonic acid-bicarbonate buffer system.

Role of the kidney in maintaining circulating buffer systems: bicarbonate reabsorption, excretion of titratable acids and ammonium ions. Metabolic and respiratory acidosis and alkalosis. Davenport diagram. Respiratory and renal compensation.

Physiology of Diuretic Action Physiological basis of diuretic action. Sites and mechanisms of action of the main classes of diuretics: osmotic diuretics, carbonic anhydrase inhibitors, loop diuretics, thiazide diuretics and potassium-sparing diuretics.

PHYSIOLOGY OF THE GASTROINTESTINAL SYSTEM AND NUTRITION

Physiology of Nutrition. Food and nutrients. Energy metabolism. Assessment of energy requirements. Energy content of foods. Measurement of energy expenditure. Direct and indirect calorimetry. Basal metabolic rate: measurement and physiological variations. Total energy requirements and calculation of daily caloric needs.

Dietary intake and nutritional requirements for proteins, lipids and carbohydrates. Dietary fibre. Beverages. Fat-soluble vitamins: A, D, E and K. Water-soluble vitamins: B1, B2, B3, B5, B6, B8, B9, B12 and C. Major minerals: calcium, phosphorus, magnesium, sodium, chloride, potassium and sulfur. Trace elements: iron, zinc, iodine and fluoride. Water balance.

Physiological mechanisms regulating hunger and satiety: central and peripheral mechanisms involved in short-term and long-term control of food intake.

Enteric Nervous System. Innervation of the gastrointestinal tract: sympathetic, parasympathetic and enteric divisions. Organization of the enteric nervous system, including ganglionated and aganglionic plexuses. Enteric neurons: morphological and functional classification and distribution.

Mechanisms of neuronal transmission. Receptors for neurotransmitters and neuromodulators. Functional interactions among enteric neurons. Neuroeffector junctions between enteric neurons and effector cells. Excitatory and inhibitory motor neurons.

Electrical and synaptic properties of enteric neurons: fast and slow excitatory postsynaptic potentials and slow inhibitory postsynaptic potentials.

Extrinsic innervation of the gastrointestinal tract. Sympathetic and parasympathetic reflexes. Endocrine regulation of gastrointestinal functions.

Gastrointestinal Motility Gastrointestinal smooth muscle activity: neural modulation, contraction and relaxation. Slow electrical waves and interstitial cells of Cajal. Extrinsic innervation. Motor functions, patterns of gastrointestinal motility and sphincter function.

Mastication and swallowing. Esophageal motility.

Gastric motility: reservoir function of the stomach, neural and endocrine regulation, and gastric accommodation. Antral pump, action potentials and contractile waves. Gastric emptying.

Motility of the small and large intestine: functional organization and patterns of motility. Interdigestive motility and the migrating motor complex. Postprandial motility. Propulsive movements and colonic mass movements. Defecation.

Gastrointestinal Secretions Salivary secretion: composition and functions of saliva and regulation of salivary secretion. Gastric secretion: morphological and functional organization of the gastric mucosa and gastric cell types. Gastric acid secretion. Gastric mucosal barrier. Electrolyte composition of gastric juice. Regulation of acid secretion. Secretion and functions of pepsin, gastric lipase, mucus and intrinsic factor. Pancreatic secretion: morphological and functional organization of the exocrine pancreas. Aqueous and enzymatic components of pancreatic secretion. Regulation of pancreatic secretion and pancreatic responses to food intake.

Biliary secretion: morphological and functional organization of the hepatobiliary system. Composition and formation of bile. Bile transport and storage. Regulation of bile release into the duodenum. Secretions of the small and large intestine.

Digestion and Absorption Digestion and absorption of carbohydrates, proteins and lipids. Absorption of vitamins. Absorption and secretion of electrolytes and water. Absorption of minerals and trace elements. Physiological mechanisms of adaptation of the gastrointestinal system.

EXERCISE PHYSIOLOGY

Introduction to exercise and sport physiology. Skeletal muscle and exercise. Metabolism and energy systems. Metabolic responses to exercise. Cardiovascular control during exercise. Respiratory regulation during exercise. Training-induced metabolic, cardiorespiratory, and muscular adaptations. Functional assessment of the athlete. Cardiopulmonary exercise testing (CPET). Methods for functional assessment of the athlete. Physiological function and aging. Aging and muscle function: sarcopenia. Physiological responses to exercise in extreme environments.

RECOMMENDED READING/BIBLIOGRAPHY

FISIOLOGIA MEDICA –Conti et al. - Editore: Edi-Ermes

FISIOLOGIA - Berne Levy et al. Editore: CEA

Fisiologia dell’esercizio L’essenziale -McArdle W.D., Katch F.I., Katch V.L.,. Piccin Editore

TEACHERS AND EXAM BOARD

LESSONS

LESSONS START

Please refer to the Web Agenda | University of Genoa, available at the following link: https://easyacademy.unige.it/portalestudenti/

Class schedule

The timetable for this course is available here: Portale EasyAcademy

EXAMS

EXAM DESCRIPTION

Written + Oral Examination

To access the oral examination, a written test, consisting of 30 multiple choice questions must be passed. A minimum score of 15 points must be achieved (the score is distributed as follows: points 1 for each right question; points: -0.25 for each wrong question; no points to unanswered questions).  In case of failing the oral test, the written test must be repeated.

ASSESSMENT METHODS

In the oral examination, the candidate's preparation is assessed by three different  Physiology lecturers. The candidate must demonstrate knowledge of general physiology and physiology of the apparatuses.

FURTHER INFORMATION

Slides of lectures presented by the lecturers are available on AulaWeb.